Surveillance video introduced by prosecutors Wednesday in the trial of Alec Baldwin’s alleged stalker shows her in the lobby of his East Village building.

The 10-second, slow-motion video – shown on WCBS TV – captures Genevieve Sabourin, 41, pacing during a visit in which she appeared angry, the building’s doorman testified.

The lovestruck French Canadian beauty spent the night in the slammer after Judge Robert Mandelbaum found her in contempt of court for her repeated outbursts, and sentenced her to 30 days in jail.

Sabourin, a film publicist and wannabe actor, said Baldwin, 55, wined and dined her before bedding her at the Lowell Hotel in February 2010.

Sabourin rages at reporters outside court yesterday

During testimony Wednesday, she provided a highly detailed account of their romantic weekend in the city, which included taking in a Broadway play and dinner at the Upper East Side hotspot Elio’s before they returned to the hotel for a steamy sex romp.

Baldlwin a day earlier denied the affair, saying he only met with Sabourin to offer her career advice as a favor to his pal Martin Bregman, producer of “Scarface” and “Dog Day Afternoon, “ among other hit flicks.

The former “30 Rock” star also claimed Bregman and Sabourin had an affair, a charge both have vehemently denied, with each branding him a liar.

Baldwin also testified he told Sabourin he wanted no further contact with her after their February encounter, though she claimed he emailed her daily for weeks and invited her to his pad in the Hamptons.

And her lawyer got Baldwin to admit that he continued emailing her until early 2012, though the MSNBC host said he was only responding to messages she sent him.

The ditzy Quebecer repeatedly interrupted the trial Tuesday, calling Baldwin a liar, heckling his testimony and insisting they had a sexual relationship.

Alec Baldwin ahead of his testimony against Genevieve Sabourin.

When she picked up where she left off early Wednesday, Mandelbaum had reached his limit.

“That’s it!” he snapped, funding her in contempt for ignoring his repeated warnings to pipe down.

Her lawyer, Todd Spodek, defended his client, saying she was a foreigner under intense pressure in a New York courtroom packed with the press, and that he hoped mandelbaum would reconsider the 30-day sentence.

Sabourin, meanwhile, was distraught over the fate of her pet Yorkie, Charlie, who she brought with her from her suburban Montreal home.